/Engine/Source/Runtime/Engine/Classes/Distributions/DistributionVectorUniformCurve.h
Get the output value for the key with the specified index on the specified sub-curve. SubIndex must be within range ie >=0 and < NumSubCurves. KeyIndex must be within range ie >=0 and < NumKeys.
virtual float GetKeyOut ( int32 SubIndex, int32 KeyIndex )